<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link rel="stylesheet" href="css/index.css">
</head>
<body>
    <div class="content">
        <div id="list">
            <img src="images/01.png" alt="">
            <img src="images/02.png" alt="">
            <img src="images/03.png" alt="">
            <img src="images/04.png" alt="">
            <img src="images/05.png" alt="">
        </div>
        <button id="prev"></button>
        <button id="next"></button>
        <div id="btns">
            <span class="current"></span>
            <span></span>
            <span></span>
            <span></span>
            <span></span>
        </div>
    </div>
    <script>
        var prev = document.getElementById("prev");
        var next = document.getElementById("next");
        var lists = document.querySelectorAll("#list>img");
        var icons = document.querySelectorAll("#btns>span")
        var index = 0;
        next.onclick=function(){
            index++;
            if(index>4){
                index=0;
            }
            console.log(index)
            for(let i=0;i<lists.length;i++){
                lists[i].style.display="none"
            }
            lists[index].style.display = "block"
            /* ++ */
            for (let i = 0; i < icons.length; i++) {
                icons[i].classList.remove("current")
            }
            icons[index].classList.add("current")
        }
        prev.onclick=function(){
            index--;
            if(index<0){
                index=4;
            }
            for(let i=0;i<lists.length;i++){
                lists[i].style.display="none"
            }
            lists[index].style.display = "block"
            /* ++ */
            for (let i = 0; i < icons.length; i++) {
                icons[i].classList.remove("current")
            }
            icons[index].classList.add("current")
        }
        for(let i=0;i<icons.length;i++){
            icons[i].index=i;
            icons[i].onclick=function(){
                let currentIndex=this.index;
                for(let i=0;i<icons.length;i++){
                    icons[i].classList.remove("current")
                }
                icons[currentIndex].classList.add("current")

                for(let i=0;i<lists.length;i++){
                    lists[i].style.display="none"
                }
                lists[currentIndex].style.display="block"
            }
        }
    </script>
</body>
</html>